(19)

(11)

EP 0 528 826 A1

(12)

(43) Date of publication: 03.03.1993 Bulletin 1993/09 (21) Application number: 91908064.0 (22) Date of filing: 19.04.1991

(51) International Patent Classification (IPC):  A01H 5/ 00( . ) C12N 9/ 42( . ) C12N 15/ 113( . ) C12R 1/ 91( . ) C12N 5/ 00( . ) C12N 15/ 00( . ) C12N 15/ 82( . ) (86) International application number: PCT/GB1991/000614 (87) International publication number: WO 1991/016440 (31.10.1991 Gazette 1991/25)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 25.04.1990 GB 19900009307 (71) Applicant: IMPERIAL CHEMICAL INDUSTRIES PLC London SW1P 3JF (GB)	(72) Inventors: BIRD, Colin, Roger Berkshire RG12 1YT (GB) RAY, John, Anthony 30 Sylvanus Wooden Hill Berkshire RG12 4XX (GB) SCHUCH, Wolfgang, Walter 14 Greenfinch Close Berkshire RG11 6TZ (GB) (74) Representative: Roberts, Timothy Wace, et al  ICI Group Patents Services Dept. PO Box 6 Shire Park Bessemer Road Welwyn Garden City, Herts, AL7 1HD Welwyn Garden City, Herts, AL7 1HD (GB)